Minor Bugfixes (With additional changes to make the source buildable)

Changes made in commits include following minor bugfixes.
* Fix to NewTheater/structure image filename handling to support YR-specific theaters.
* Fix to loading buildingz.shp for YR (has different file extension there).
* Fix for a crash that happens when saving PNG render images (used to assume certain string contains a substring that differs between JPEG/PNG rendering).

Additionally following changes were made to CNCMaps.Objects.Westwood to allow one to build that project.
* Removed duplicate classes.
* Added necessary references to other projects.
* Commented out obviously incomplete code.